Hi richpanda,
Thanks for reporting this issue, and sorry to hear that AdSense rejected your signup.
We are not Google AdSense and therefore do not have an exact insight into the confirmation of new websites. Therefore, I can only guess what the problem is in your case.
I assume that the content on your site is unique and not taken from other sites.
Technically, your website is error-free and in good shape. The topic of finance is also unproblematic, as long as the focus is not exclusively on cryptocurrencies.
I guess that you have too little content on the site so far. I would register a website only after 3-6 months and wait until 20-30 pages or articles are published there.
That’s why I would publish more content and repeat the registration with Google AdSense in a few weeks. Until then, you could try to monetize your site with another ad network.
Here, you can find AdSense official information about websites that are ready to get approved.
Best regards,
Joachim